Heretofore, various materials have been proposed as flame or fire retardants. For instance, in the field of fire resistant cable transits, such materials based on neoprenes, silicon foam, inorganic molding materials and mineral wool mats have been utilized. While these known materials exhibit various useful insulation and resistance to fire hazzard properties, none of them, simultaneously, exhibits (1) good thermal conductivity under normal use conditions, (2) expansion and plugging properties at elevated temperatures and (3) heat insulating and mechanical protective properties at very high temperatures, such as are encountered during a fire.
The present invention, however, is directed to a fire or flame barrier material which, in addition to exhibiting the above-mentioned characteristics, also has, simultaneously, additional operational and flame or fire resistant properties, and is capable of being produced using relatively inexpensive processes and components.